Kristin Cavallari Brother's Death Ruled Accidental

Police said the autopsy report closes the case, but questions may forever linger about what exactly happened to the reality star's brother, Michael Cavallari.

SALT LAKE CITY (AP) — A medical examiner has determined NFL quarterback Jay Cutler's brother-in-law's death was accidental, saying Michael Cavallari died of hypothermia after he crashed his car during a frigid temperatures while passing through a rocky and rural part of southern Utah.

Grand County Sheriff officials announced the findings on Tuesday in a news release. The 30-year-old Michael Cavallari is the brother of reality TV personality Kristin Cavallari.

Grand County Sheriff Steven White said they are waiting on toxicology reports to find out if Michael Cavallari had any drugs in his system. White said the autopsy report closes the case, but questions may forever linger about what exactly happened.

His body was found at the bottom of a steep hillside filled with boulders on Dec. 10, about two weeks after his abandoned car was found with the engine running and the air bag deployed about 200 miles south of Salt Lake City.

Temperatures in the area were at or below freezing every night in the days after the car was found up against a small embankment.

"I don't know if he thought he saw lights or something and started walking?" White said. "We just don't know."

Investigators believed he was just passing through Utah, but they don't know where he was headed or what he was doing in Utah.

Cavallari's family was notified earlier this week, White said.

Kristin Cavallari declined comment through her publicist.

Michael Cavallari had been arrested in California four days before his car was found on allegations that he acted threateningly toward a woman and had a gun.

He bailed out of jail on Nov. 25. Two days later, a rancher discovered the car near a dirt road about five miles from Interstate 70.

He was single and had no children.

Kristin Cavallari rose to fame in the mid-2000s when she appeared in the MTV reality series Laguna Beach and The Hills. She is married to Cutler, who starred at Vanderbilt University and now plays for the Chicago Bears. The couple has three children together.